So this is a wooden stand meant to hold a banner pole vertical.
In Japanese, I'm not quite sure what to call it.
The most likely candidates are hatadai, daiwaku, and hatazaotate.

Banner Stand

It's made entirely of pine, with no fasteners.
I hand cut 20 mortise and tenon joints for assembly with glue.
I darkened it with
tannic acid (tea)
and iron acetate (steel wool dissolved in white vinegar),
then finished it with boiled linseed oil.

I was able to make it with wood I already had in the basement,
including some mysterious 2x2 that was here when Sharon moved in
more than 15 years ago.